1. Field of the Invention
The invention relates generally to wireless electronic devices. In particular, the invention relates to the use of wireless electronic devices for position tracking.
2. Description of the Prior Art
Position tracking involves identifying an entity's location in a pre-defined space (e.g., two dimensional or three dimensional space). Certain methods for position tracking involve the use of a wireless transmitter/transducer (e.g., an electronic tag) that is tracked by an array of receiver devices. For example, one method to track the position of a radio signal emitting tag is to use the tag (of which there may be more than one) signal's amplitude or the tag signal's time differences of arrival at various receiver devices at known locations to determine the tag's position. By comparing the tag's signal time of arrival, time difference of arrival, or signal strength at each receiver's known position, a position tracking system uses triangulation or trilateration to determine the position of the tag.
In these types of position tracking systems, at least three receiver devices at known positions are needed to determine a two dimensional position recording of the tag, and at least four receiver devices at known positions are needed to determine a three dimensional position recording of the tag. The receiver devices in these types of position tracking systems each include a receiver antenna and a receiver channel.